U.S. patent number 6,470,943 [Application Number 09/834,426] was granted by the patent office on 2002-10-29 for apparatus for making an absorbent pad for use in absorbent articles.
This patent grant is currently assigned to Kimberly-Clark Worldwide, Inc.. Invention is credited to Kenneth Thomas Borowski, Norman Earl Brown, Leon Eugene Chambers, Jr., John Christopher Garstka, Joseph Michael Kugler, David Charles Musil, James George Van Himbergen, Edward Erich Werner.
United States Patent |
6,470,943 |
Borowski , et al. |
October 29, 2002 |
Apparatus for making an absorbent pad for use in absorbent
articles
Abstract
Methods and systems for making an absorbent pad for use in an
absorbent article utilize a forming device for forming material
into an absorbent core, a supply device for supplying a containment
layer against the first surface of the absorbent core and spray
apparatus for spraying fibers of molten resin onto the second
surface of the absorbent core. The fibers form a stabilization
layer on the absorbent core that increases the integrity of the
absorbent core. The spray apparatus includes a nozzle having a
resin aperture for exhausting resin therefrom and multiple gas
apertures for exhausting gas therefrom to provide a random pattern
to the fibers of molten resin as the fibers are sprayed onto the
second surface. Resin can also be sprayed onto first and second
portions of the containment layer extending outwardly from edges of
the absorbent core so the containment layer and the stabilization
layer encompass the absorbent core. In another embodiment, a second
containment layer can be placed on the second surface of the
absorbent core and first and second stabilization layers can be
spaced outwardly therefrom and deposited on the absorbent core.
Inventors: |
Borowski; Kenneth Thomas
(Appleton, WI), Kugler; Joseph Michael (Greenville, WI),
Van Himbergen; James George (Kimberly, WI), Brown; Norman
Earl (Lithonia, GA), Chambers, Jr.; Leon Eugene
(Appleton, WI), Garstka; John Christopher (Appleton, WI),
Musil; David Charles (Neenah, WI), Werner; Edward Erich
(Oshkosh, WI) |
Assignee: |
Kimberly-Clark Worldwide, Inc.
(Neenah, WI)
|
Family
ID: |
56289773 |
Appl.
No.: |
09/834,426 |
Filed: |
April 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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438134 |
Nov 10, 1999 |
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874500 |
Jun 13, 1997 |
6060115 |
May 9, 2000 |
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Current U.S.
Class: |
156/390; 156/501;
156/522; 156/510 |
Current CPC
Class: |
A61F
13/539 (20130101); D04H 1/72 (20130101); Y10T
156/1343 (20150115); Y10T 156/12 (20150115); Y10T
156/1085 (20150115) |
Current International
Class: |
A61F
13/15 (20060101); D04H 1/70 (20060101); B32B
035/00 () |
Field of
Search: |
;156/167,242,246,270,279,324,500,501,510,516,349,390,522
;427/200 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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41 14 839 |
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Nov 1992 |
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DE |
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0 534 863 |
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Mar 1993 |
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EP |
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0 658 351 |
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Jun 1995 |
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EP |
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0 685 213 |
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Dec 1995 |
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EP |
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WO 95/31167 |
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Nov 1995 |
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WO |
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Primary Examiner: Mayes; Curtis
Attorney, Agent or Firm: Wilhelm Law Service Wilhelm; Thomas
D.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application, Ser. No.
09/438,134 which was filed on Nov. 10, 1999, which is a divisional
application of Ser. No. 08/874,500, filed Jun. 13, 1997, now U.S.
Pat. No. 6,060,115, issued May 9, 2000, which claims benefit of
provisional application Serial No. 60/034,426, filed on Dec. 17,
1996, all of which are incorporated herein by reference in their
entireties.
Claims
Having thus described the invention, what is claimed is:
1. A system for fabricating an absorbent pad, said system
comprising: (a) a forming device for forming material into an
absorbent core having first and second opposing surfaces and first
and second opposing edges; (b) a supply device for supplying a
pre-formed containment layer against the first surface of the
absorbent core; and (c) spray apparatus for spraying fibers of
molten resin onto the second surface of the absorbent core, thereby
depositing a permeable stabilization layer on the second surface
such that the resin fibers interact with the absorbent core to
increase the integrity of the absorbent core.
2. A system as in claim 1, said forming device having the capacity
to form the absorbent core as a continuous absorbent sausage having
a length, the absorbent sausage comprising a continuous air formed
layer of fiber extending along the length thereof.
3. A system as in claim 1, said forming device including a
fiberizer, a forming chamber and a rotatable forming drum for
forming said absorbent core thereon.
4. A system as in claim 3, said forming device including a scarfing
roll for shaving material from said absorbent core to reduce the
thickness of said absorbent core.
5. A system as in claim 1, said spray apparatus comprising at least
one nozzle having a resin aperture for exhausting resin therefrom,
and multiple gas apertures for exhausting gas therefrom.
6. A system as in claim 5, said spray apparatus comprising a nozzle
assembly having a plurality of said nozzles depositing molten resin
onto the second surface of said absorbent core.
7. A system as in claim 6, said plurality of nozzles defining an
array extending across the width of said formed absorbent core, and
depositing the molten resin across a width of from about 2.5 inches
to about 10 inches.
8. A system as in claim 1, aid spray apparatus comprising a
meltspray assembly for directing the resin toward the second
surface of the absorbent core as a spray of molten fibers.
9. A system as in claim 8, said meltspray assembly including a
recirculation line for recirculating the resin from a melt tank
such that the resin remains molten whether or not the spray
apparatus is applying the resin as a spray of molten fibers.
10. A system as in claim 1, including a vacuum transfer device,
said vacuum transfer device receiving the absorbent core from said
forming device prior to application of the molten resin to the
second surface.
11. A system as in claim 1, including a trimming device for
trimming the containment layer from about the absorbent core.
12. A system as in claim 11, said forming device forming the
absorbent core as a continuous length absorbent sausage, said
system including a severing device for periodically severing said
absorbent sausage into respective absorbent pads.
13. A system as in claim 12, including a main tacker for securing
each respective absorbent pad between a respective bodyside liner
and a respective outer cover, in forming an absorbent article, the
stabilization layer being adjacent the outer cover.
14. A system as in claim 13, including a severing device for
periodically severing the bodyside liner and the outer cover to
form absorbent articles.
15. A system as in claim 1, first and second portions of the
containment layer extending outwardly from the first and second
opposing edges of the absorbent core, said spray apparatus
depositing molten resin onto at least part of the first and second
portions of the containment layer such that the molten resin cools
and becomes hard, and interacts with the absorbent core at the
second surface to increase the integrity of the absorbent core.
Description
FIELD OF THE INVENTION
Absorbent articles Such as infant diapers, training pants, adult
incontinence products, and the like are well known. Such articles
have achieved a wide acceptance due to their ability to receive and
absorb body exudates.
BACKGROUND OF THE INVENTION
In general, absorbent articles are formed by multiple webs of
material. Such webs generally include a bodyside liner and outer
cover on opposing outside surfaces of the absorbent article. An
absorbent core generally is located between the bodyside liner and
the outer cover. The absorbent core generally has preformed barrier
tissue located on a first surface, positioned between the absorbent
core and the bodyside liner, and preformed forming tissue located
on an opposing second surface, positioned between the absorbent
core and the outer cover. The barrier tissue and forming tissue, in
combination, completely surround and support the absorbent
core.
European Patent Application 0 685 213 A2 published Dec. 6, 1995
discloses depositing fibers onto one surface of absorbent core
material to provide a cover. Once the cover of fibers has been
deposited and adhered to the absorbent core material, the absorbent
core is spirally wound and radially compressed to form a tampon.
The fibers at least partially adhere to the surface of the
absorbent core material onto which they are deposited. The fibers
form an outer cover on the absorbent material.
U.S. Pat. Nos.5,227,107 and 5,409,768 to Dickenson et al disclose
forming devices including forming chambers for forming absorbent
structures. The Dickenson et al teachings include meltspraying
polymer into the forming chamber, along with other fibers, to form
an absorbent core. The meltsprayed polymer is mixed with the
absorbent fibers and forms an absorbent structure including
meltsprayed fibers dispersed internally in the absorbent core.
SUMMARY OF THE DISCLOSURE
The present invention relates to methods and systems for making
absorbent pads for use in absorbent articles. Opposing surfaces of
an absorbent core are supported by a preformed containment layer
and a stabilization layer of resin fiber. More particularly, the
methods include forming an absorbent core of material in a forming
device, applying the pre-formed containment layer against a first
surface of the absorbent core, and depositing the stabilization
layer comprising resin fiber onto a second surface of the absorbent
core. The resin fiber interacts with the absorbent core at the
second surface to increase the integrity of the absorbent core. The
first containment layer can be applied to the first surface of the
absorbent core prior to depositing the stabilization layer onto the
absorbent core or after depositing the stabilization layer onto the
absorbent core. The method can be devoid of the step of joining a
second previously-formed containment layer with material on the
second surface of the absorbent core.
In preferred embodiments, resin fibers are deposited onto the
second surface of the absorbent core in a random pattern while the
fibers are in such condition that properties of the fibers
contribute to securement of the fibers to the absorbent core at the
second surface. The resin fibers can comprise polyolefins, such as
polypropylene.
In some embodiments, the resin fiber is deposited onto the second
surface of the absorbent core using a spray nozzle assembly
comprising a plurality of nozzles.
The nozzles in the spray nozzle assembly can be arranged in an
array extending across the width of the formed absorbent core. The
plurality of nozzles can apply the resin fiber across a width, of
the absorbent core, of from about 2.5 inches to about 10 inches.
Each nozzle preferably includes a single resin aperture exhausting
the resin fiber therefrom, and multiple gas apertures directing the
resin fiber exhausted therefrom toward the absorbent core, and
imparting a random pattern to each such fiber.
In some embodiments, the resin fibers may be deposited onto the
second surface in such condition that some of the fibers bond to
the absorbent core at the second surface, and to each other at
resin fiber crossing points. The resin fiber directed toward the
absorbent core can comprise a spray of molten fibers.
Some embodiments of the method include drawing a vacuum on a
rotating forming drum of the forming device and thereby assisting
in drawing absorbent material toward the drum in the step of
forming the absorbent core.
In most embodiments, the absorbent sausage, including the
containment layer and the stabilization layer, is severed at spaced
locations along the length thereof, to form individual absorbent
pads. The absorbent pad is mounted to a bodyside liner, such that
the containment layer is located between the bodyside liner and the
absorbent pad. An outer cover is mounted to the second surface of
the absorbent pad, such that the stabilization layer is located
between the absorbent pad and the outer cover.
In some embodiments, the containment layer has first and second
edge portions extending outwardly from the first and second
opposing edges of the absorbent core. The fibers of the
stabilization layer are deposited onto at least part of the first
and second edge portions of the containment layer while the fibers
are in condition to contribute to securement of the fibers to the
containment layer. The fibers become secured to the containment
layer, and subsequent cooling of the fibers causes the fibers to
lose their securement characteristic, while retaining securement to
the containment layer. The containment layer and stabilization
layer can entirely encompass the absorbent core.
Another embodiment includes a system for fabricating an absorbent
pad comprising a forming device for forming material into an
absorbent core, a supply device for supplying a pre-formed
containment layer against the first surface of the absorbent core,
and spray apparatus for spraying fibers of molten resin onto the
second surface of the absorbent core, thereby depositing a
stabilization layer onto the second surface such that the resin
fibers interact with the absorbent core to increase the integrity
of the absorbent core. The absorbent core can comprise a continuous
absorbent sausage, the absorbent sausage being a continuous air
formed layer of fiber.
In some embodiments, the forming device includes a fiberizer, a
forming chamber and a rotatable forming drum, preferably a vacuum
forming drum, for forming the absorbent core. The forming device
can also include a scarfing roll for shaving material to reduce the
thickness of the absorbent core.
In some embodiments, the spray apparatus includes at least one
nozzle having a resin aperture for exhausting resin therefrom, and
multiple gas apertures for exhausting gas therefrom. The spray
apparatus can comprise a nozzle assembly having a plurality of
nozzles depositing molten resin onto the second surface of the
absorbent core. The plurality of nozzles can define an array of
nozzles extending across the width of the formed absorbent core,
and can deposit molten resin across a width, of the absorbent core,
of from about 2.5 inches to about 10 inches.
In some embodiments, the spray apparatus comprises a meltspray
assembly for directing molten resin toward the second surface of
the absorbent core as a spray of molten fibers.
In some embodiments, the system includes a vacuum transfer device
for receiving the absorbent core from the forming device prior to
application of resin to the second surface of the absorbent core.
The first surface of the absorbent core and the corresponding
containment layer are disposed toward the vacuum transfer
device.
In some embodiments, the system includes a trimming device for
trimming the containment layer about the absorbent core.
In some embodiments, an absorbent sausage severing device
periodically severs the absorbent sausage, including the
containment layer and stabilization layer, to form respective
absorbent pads.
In preferred embodiments, a main tacker secures each respective
absorbent pad between a respective bodyside liner and a respective
outer cover, the stabilization layer being adjacent the outer
cover.
In typical embodiments, a severing device periodically severs the
bodyside liner and the outer cover to thereby form respective
absorbent articles.
In some embodiments, first and second portions of the containment
layer extend outwardly from first and second opposing edges of the
absorbent core. The spray apparatus deposits resin fiber onto at
least part of the first and second portions of the containment
layer such that the resin fiber interacts with the containment
layer, thereby contributing to securement of the resin fiber to the
containment layer.
In another embodiment, the system makes an absorbent article
comprising a chassis. The chassis is formed of an outer cover, and
a bodyside liner mounted to the outer cover and contacting the body
of a user. An absorbent core is disposed between the bodyside liner
and the outer cover. A pre-formed containment layer is disposed
between the bodyside liner and the first surface of the absorbent
core. A stabilization layer of resin fiber is disposed between the
absorbent core and the outer cover. The stabilization layer
interacts with the absorbent core at the second surface to increase
the integrity of the absorbent core.
In most embodiments, the stabilization layer comprises fibers
deposited on the second surface in a random pattern, properties of
the fibers contributing to securement to the second surface. The
fibers are typically secured to each other at crossover points. The
fibers can comprise polymeric material.
In some embodiments, the containment layer has first and second
portions extending outwardly from opposing edges of the absorbent
core, the stabilization layer being secured to the containment
layer at at least part of the first and second portions, the
containment layer and the stabilization layer, in combination,
encompassing the absorbent core.
In most embodiments, the containment layer comprises barrier tissue
and the stabilization layer comprises a material that is not
generally considered to be an adhesive.
In another embodiment a narrow second containment layer is placed
along the length of the second surface of the absorbent core. First
and second stabilization layers are then spaced on either side of
the second containment layer. The stabilization layers can be
secured to only the absorbent core, or more nozzles can be selected
such that the molten fibers of the first and second stabilization
layers can contact the second containment layer and the first
containment layer thus securing the containment layers to the
absorbent core.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows diagrammatically a system for making an absorbent pad
of the invention for use in an absorbent article.
FIG. 2 shows a top view of a length of an absorbent sausage, and a
spray nozzle assembly, taken at 2--2 of FIG. 1.
FIG. 3 shows a top view as in FIG. 2 wherein the resin is applied
over a greater width of the combination of the absorbent
sausage.
FIG. 4 shows a photomicrograph of a section of an actual
representative stabilization layer of FIG. 3.
FIG. 5 shows representatively, the arrangement of the nozzles in
the spray nozzle assembly, as viewed from the vacuum transfer
device.
FIG. 6 shows the resin fiber output end of a single nozzle useful
in the invention.
FIG. 7 shows a second embodiment of systems of the invention for
making an absorbent pad.
FIG. 8 shows a top view of a length of an absorbent sausage, taken
at 8--8 of FIG. 7.
FIG. 9 shows a top view as in FIG. 8 wherein the resin has been
applied over a greater width of the combination of the absorbent
sausage and the containment layer.
FIG. 10 shows another embodiment of the invention wherein a second
containment layer is applied to the second surface of the absorbent
sausage.
FIG. 11 shows a top view of a length of the absorbent sausage, and
a spray nozzle assembly, taken at 11--11 of FIG. 10.
FIG. 11A shows a top view of a length of the absorbent sausage, and
a spray nozzle assembly, taken at 11--11 of FIG. 10, the spray
nozzle assembly spraying stabilization layers onto the first and
second containment layers, and portions of the absorbent
sausage.
FIG. 12 shows a block diagram of further processing apparatus which
act on the absorbent sausage of the invention to form an absorbent
article.
FIG. 13 shows a top view of a length of the absorbent sausage of
the invention after portions of the containment layer have been
trimmed away.
FIG. 14 shows a top view of a completed absorbent article made with
an absorbent pad of the invention.
FIG. 15 shows a cross-sectional view of a completed absorbent
article taken at 15--15 of FIG. 14.
The invention is not limited in its application to the details of
the construction and the arrangement of the components set forth in
the following description or illustrated in the drawings. The
invention is capable of other embodiments or of being practiced or
carried out in various ways. Also, it is to be understood that the
terminology and phraseology employed herein is for purpose of
description and illustration and should not be regarded as
limiting. Like reference numerals are used to indicate like
components. The drawings are for purposes of illustration, and are
not necessarily drawn to scale.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
The present invention is directed toward methods and systems for
making an absorbent pad for use in an absorbent article. An
exemplary method replaces forming tissue with sprayed molten resin
to increase the integrity of the absorbent core. Such practice
maintains the overall integrity of the absorbent article while
reducing the cost of production.
FIG. 1 shows a first system 8 for fabricating an absorbent core.
System 8 includes a fiberizer 10, contained in a forming chamber 12
for receiving absorbent material, and a forming drum 14 which
rotates, generally continuously, in the direction of arrow 15.
System 8 also includes a scarfing roll 16. Scarfing roll 16 shaves
excess absorbent material from an absorbent sausage 20 formed by
forming drum 14. A vacuum transfer device 32 delivers absorbent
sausage to nip rolls 58A, 58B. A supply device 22, turning rolls
24, 26, and transfer conveyor 28, deliver a pre-formed containment
layer 30 to nip roll 58A. At nip rolls 58A, 58B, containment layer
30 is secured to a first surface 34 of absorbent sausage 20.
A heated melt tank 42 receives particulate resin from a storage
hopper 44 and heats the resin to a molten state. A heated resin
delivery line 46 delivers the melted thermoplastic resin to a
heated spray nozzle assembly 38. A heated recirculation line 48
recirculates unused resin back to melt tank 42 for reuse.
A compressed gas supply 52 supplies compressed gas to a gas heater
50. Gas heater 50 heats the compressed gas, as necessary. A supply
line 54 supplies the heated compressed gas to spray nozzle assembly
38. A spray nozzle assembly 38 sprays a resin fiber 40 onto a
second surface 36 of absorbent sausage 20 to form a stabilization
layer 65.
In the context of the invention, "absorbent sausage" refers to any
absorbent material or combination of absorbent materials having a
generally continuous length, and can also include superabsorbent
materials.
"Absorbent pads" refers to cut lengths of the absorbent sausage,
including containment layer 30 and stabilization layer 65, that can
be placed in absorbent articles.
"Absorbent core" 20C, shown in FIG. 14, refers to an appointed
fibrous batt segment individually formed on forming drum 14.
Absorbent core 20C includes absorbent material used for forming the
absorbent sausage, but does not include any stabilization layer or
containment layer applied thereto.
Absorbent sausage 20 is deposited from vacuum transfer device 32
onto transfer conveyor 56, and advances on the transfer conveyor
toward first and second nip rolls 58A, 58B comprising debulker 60.
At debulker 60 the preformed containment layer is secured to
absorbent sausage 20. Absorbent sausage 20 then advances to
transfer conveyor 62. Arrow 64 indicates a path leading absorbent
sausage 20 toward further processing stations not shown in FIG.
1.
Fiberizer 10 fiberizes absorbent material in forming chamber 12.
Thus fiberizer 10 breaks up boards of fiber material to form
individualized fluff. Absorbent sausage 20 comprises a matrix of
generally hydrophilic fibers, such as a web of cellulosic fluff,
preferably in combination with a particulate highabsorbency
material commonly known as superabsorbent material. In a particular
embodiment, absorbent sausage 20 comprises a mixture of
superabsorbent hydrogel-forming particles and wood pulp fluff
fibers. In place of the wood pulp fluff, one may use any of a
variety of synthetic fibers, a combination of synthetic fibers, or
a combination of synthetic fibers and natural fibers. At least part
of the absorbency of the absorbent material can also be derived
from capillary action resulting from the arrangement of fibers with
respect to each other. Absorbent sausage 20 preferably does not
contain any meltsprayed polymeric material internal to its
structure. Absorbent sausage 20 preferably comprises a continuous
layer of air formed fiber.
Forming drum 14 forms absorbent sausage 20 using gravity, and a
vacuum chamber (not shown) contained in the forming drum. A vacuum
generating apparatus (not shown) generates an air flow which, in
combination with the vacuum chamber and apertures (not shown) in
the forming surface of forming drum 14, assists in drawing
absorbent material 18 onto the forming surface of the drum. The
amount of vacuum supplied by the vacuum generating apparatus can be
varied, turned off, or blocked, to meet the specific needs of the
particular absorbent sausage 20 being formed. For instance, at the
point absorbent sausage 20 must be released and transferred to
vacuum transfer device 32, the vacuum at the area of transfer can
be blocked on forming drum 14. One example of forming devices for
use with the invention is set forth in FIGS. 17-19 of U.S. Pat. No.
5,227,107, the disclosure of which is hereby incorporated by
reference in its entirety.
In most embodiments, forming drum 14 comprises a first sausage
carrier, and vacuum transfer device 32 comprises a second sausage
carrier. In certain instances, formed absorbent sausage 20 may
desirably be contoured in shape, or shaved to reduce thickness. As
suggested by FIG. 1, scarfing roll 16 shaves absorbent sausage 20
while the sausage is on forming drum 14, and before transfer of the
absorbent sausage to vacuum transfer device 32.
While FIGS. 1-3 show absorbent sausage 20 as a continuous web of
material, absorbent cores of absorbent material 18 can also be
formed as separate individual cores on forming drum 14. Such an
arrangement obviates severing at spaced locations of absorbent
sausage 20 to create individual absorbent cores at a later step. In
any event air laid absorbent cores are formed directly on forming
drum 14.
The vacuum apertures (not shown) on forming drum 14 can be arranged
such that forming chamber 12 forms a shaped absorbent sausage 20.
Absorbent sausage 20 can, for example, be formed in a "r" shape, as
shown in FIGS. 2, 3, 8, 9, 11, 11A, 13, and 14, an hourglass shape,
or any other shape useful for an absorbent article.
Pre-formed containment layer 30 preferably comprises barrier
tissue. A typical such barrier tissue is a single-ply, low porosity
creped wadding or the like. Other tissues can also function as the
containment layer provided the proper porosity and other
characteristics are present An exemplary barrier tissue has a basis
weight of 12.5 pounds/ream, a porosity of approximately 90 cubic
feet per minute per foot squared, and strength of about 500
grams.
Containment layer 30 is drawn around turning rolls 24, 26 and on
transfer conveyor 28 to nip roll 58A. Nip rolls 58A, 58B place
containment layer on first surface 34 of absorbent sausage. 20.
In another potential embodiment (not shown), containment layer 30
advances from conveyor 28 to an outer surface of vacuum transfer
device 32. After placement of containment layer 30 on vacuum
transfer device 32, or almost simultaneously therewith, absorbent
sausage 20 is transferred onto vacuum transfer device 32. A second
vacuum generating apparatus (not shown) assists vacuum transfer
device 32 in maintaining containment layer 30 and absorbent sausage
20 thereon. The porosity of containment layer 30 must be sufficient
to allow enough vacuum through the containment layer to support
absorbent sausage 20 on vacuum transfer device 32. This is so
because the containment layer generally is positioned between the
first surface 34 of the absorbent sausage and the outer surface of
vacuum transfer device 32. Thus such an embodiment is not
contemplated as being particularly effective unless the porosity of
containment layer 30 is very large.
While vacuum transfer device 32 supports absorbent sausage 20,
spray nozzle assembly 38 deposits molten and/or semi-molten resin
fibers 40 onto opposing second surface 36 of absorbent sausage 20,
thereby forming stabilization layer 65. FIG. 2 shows spray nozzle
assembly 38 applying resin fiber 40 along a continuous length of a
middle section of absorbent sausage-20 between opposing outside
edges 66, 68 of the absorbent sausage. Arrow 70 represents the
direction of movement of absorbent sausage 20 in the process. Resin
fiber 40 quickly cools and hardens to form stabilization layer
65.
In the embodiment of FIG. 2, for example, the system of FIG. 1
deposits resin fibers 40 at the central portion of absorbent
sausage 20 to form stabilization layer 65. In this embodiment not
all of the individual nozzles of spray nozzle assembly 38 need
operate to deposit resin fiber 40.
In the embodiment of FIG. 3, more individual nozzles of spray
nozzle assembly 38 deposit resin fibers 40 across the entire width
"W" of absorbent sausage 20. Thus, some amount of meltspray between
ears 21 of absorbent sausage 20 is overspray and wasted. In later
embodiments, when the meltspray is applied, containment layer 30 is
in surface-to-surface contact with the opposite surface of
absorbent sausage 20 and thus receives the overspray. In such an
arrangement, the overspray secures stabilization layer 65 to
containment layer 30.
In other embodiments, spray nozzle assembly 38 includes at least
some intermittently operated individual nozzles that form the spray
pattern that corresponds to the shape of the absorbent sausage 20
with minimal overspray. Thus, the amount of resin fibers 40
utilized can be conserved and the cost of the process reduced.
Stabilization layer 65 shown deposited on second surface 36 of
absorbent sausage 20 in FIGS. 2 and 3 is for purposes of
illustration only. FIG. 4 shows a detailed photomicrograph showing
a section of an actual representative stabilization layer 65.
Stabilization layer 65 preferably comprises resin fibers 40 which
are composed of multiple individual fibers forming a random
web-like pattern as shown in FIG. 4. At crossing points where one
fiber intersects another, the molten fibers directly bond to one
another without adhesive. Stabilization layer 65 is permeable to
liquids and gases. Where the molten resin fibers 40 contact second
surface 36 of absorbent sausage 20, the fibers can interact with
the individual absorbent fluff fibers to increase the integrity of
the absorbent sausage structure. For instance, molten resin fibers
40 may have sufficient tackiness and deformability to conform to
and mechanically bond to the fibers in absorbent sausage 20, or
containment layer 30, if it is present when meltspraying occurs.
Desirably, fibers 40 have substantially no adhesive or tacky
characteristics after cooling to ambient temperature. The direct
bonding of fibers 40 to second surface 36 of absorbent sausage 20
preferably occurs before the fibers are fully cooled. Fibers 40
cool very quickly toward room temperature, which solidifies and
hardens the fibers. Fibers 40 first cool on their outer surface
while the interior of the fibers remains molten for a longer period
of time. As a result, fibers 40 tend to deform and wrap about the
fluff fibers of the absorbent material. Therefore, thicker fibers
40 tend to perform better than thinner fibers with respect to
deformation and securement to absorbent sausage 20. The ability to
deform, and other properties of fibers 40, assist in stabilizing
the fluff fibers and as a result help contain fluff fibers and
superabsorbent material within absorbent sausage 20. Thus fibers 40
form stabilization layer 65 and are secured to absorbent sausage 20
at second surface 36.
The random weblike pattern of stabilization layer 65 shown in FIG.
4, and the structural characteristics of fibers 40 which make up
the layer assist in stabilization of the absorbent material,
including fluff fibers and any superabsorbent material, of
absorbent sausage 20. Therefore, the random weblike pattern of
stabilization layer 65 improves the overall integrity of absorbent
sausage 20. Stabilization layer 65 also helps to protect the outer
cover from e.g. penetration by particles of superabsorbent
material. Therefore, stabilization layer 65 of fibers 40 replaces
the use of forming tissue between an absorbent core and an outer
cover in an absorbent article. Thus the system and method are
typically devoid of joining a previously-formed containment layer
with the absorbent material on second surface 36 of absorbent
sausage 20. Further, depositing resin fibers 40 as stabilization
layer 65 is less expensive than applying a preformed tissue layer
to absorbent sausage 20. In a preferred embodiment, stabilization
layer 65, on absorbent sausage 20, has a weight of about 2 to about
12 grams per square meter.
In the context of the invention, the term "resin" refers to any
solid or liquid organic material of natural or synthetic origin
that has a melting point and is generally polymeric. The
thermoplastic resin can comprise polymers such as polyolefins. For
instance, the resin can comprise polyethylene, polypropylene, or
the like. Further, the thermoplastic resin can comprise
combinations of various polymers. The melting point or points of
resin fibers 40 typically are in a range between about 140 degrees
Celsius and about 260 degrees Celsius.
European Patent Application 0 658 351A1 to Korpman, published Jun.
21, 1995, is hereby incorporated by reference in its entirety.
Korpman discloses thermoplastic polymers that can be utilized in
forming microfibers effective in some embodiments of the invention.
Desirably the thermoplastic resins used to form stabilization layer
65 of the invention do not include pressure sensitive adhesive
materials in amounts which could, by themselves activate securement
or other attachment of stabilization layer 65 to absorbent core 20
or a bodyside liner. Neither do they include a similar amount of
any other composition generally known as an adhesive material.
The overall spray apparatus for applying fibers 40 is preferably a
meltspray apparatus. Exemplary such meltspray apparatus includes
melt tank 42 which receives particulate resin material from hopper
44. A preferred melt tank comprises a grid melter, Model MX40110,
manufactured by Nordson Corp. of Duluth, Ga.
Melt tank 42 includes a heating apparatus (not shown) for melting
the thermoplastic resin and maintaining the resin in a molten
state. Melt tank 42 maintains thermoplastic resin at a desired
temperature. Heated resin delivery line 46 delivers molten resin to
spray nozzle assembly 38. Heated resin recirculation line 48
returns excess molten resin to melt tank 42. Ongoing circulation of
resin through lines 46 and 48 helps maintain appropriate
temperature and pressure in spray nozzle assembly 38, and thus
prevents cooling and hardening of the resin inside the spray nozzle
assembly or delivery line 46. For example, if spray nozzle assembly
38 stops spraying thermoplastic resin fibers 40, recirculation line
48 and delivery line 46, in combination, continuously provide
molten resin to the spray nozzle assembly. Further, the temperature
of thermoplastic resin in spray nozzle assembly 38 can be readily
controlled, and dynamically adjusted, by adjusting the rate of flow
of resin through lines 46, 48 and/or by adjusting the temperature
of the resin in melt tank 42. The temperature of polypropylene
resin preferably is between about 204 degrees Celsius and about 232
degrees Celsius.
Compressed gas supply 52 provides compressed gas to gas heater 50.
Gas heater 50 heats the compressed gas to the desired temperature.
Heated gas supply line 54 carries the heated compressed gas from
gas heater 50 to spray nozzle assembly 38. The compressed gas is
delivered to nozzle assembly 38 to control the pattern of fibers 40
being applied to absorbent sausage 20 as will be described later in
greater detail. The compressed gas preferably is heated to a
temperature similar to the temperature of the resins being applied
to the absorbent sausage 20 and at a pressure of about 40 to about
70 pounds per square inch gauge (PSIG).
FIG. 5 shows the side of spray nozzle assembly 38 which faces
absorbent sausage 20. An array of eleven nozzles 76 is shown
extending across the length of spray nozzle assembly 38. Each
nozzle 76 can be considered a separate module and is supplied with
molten resin via a gear pump. As shown in FIGS. 2 and 3, spray
nozzle assembly 38 is positioned so nozzles 76 are located at
spaced locations across the width "W" of absorbent sausage 20 and
containment layer 30. As a result, selected nozzles 76 can exhaust
resin fibers 40 across the width "W" of absorbent sausage 20 to
form stabilization layer 65.
While eleven nozzles are shown, any number of nozzles can be
utilized. Similarly, one or more of the nozzles in a nozzle array
may be blocked off to limit the number of nozzles used for a
particular operation. For example, fewer nozzles (such as three
nozzles) may be used to form the narrow spray pattern of
stabilization layer 65 shown in FIG. 2, and more nozzles (such as
five nozzles) may be used to form the wider spray pattern indicated
for stabilization layer 65 shown in FIG. 3. Further, while FIG. 5
shows one row of nozzles 76, second and additional rows can be
utilized to increase the amount of material used to form
stabilization layer 65 on second surface 36 of absorbent sausage
20, or the rate at which material is applied, or to provide more
uniform distribution of such material. For instance, in one
preferred arrangement, a second row of eleven nozzles (not shown)
aligned in the machine direction and offset in the cross machine
direction from the first row of nozzles 76 can be provided in
addition to the first row of nozzles. In a typical meltspray
embodiment, the individual nozzles comprise modules spaced
approximately one inch apart.
The number and spacing of nozzles 76 in spray nozzle assembly 38 is
sufficient to permit the application of stabilization layer 65
across a width of the absorbent sausage 20 preferably from about
2.5 inches (narrow spray pattern) to at least about 10 inches (wide
spray pattern). Additional nozzle assemblies can be used to apply a
wider stabilization layer 66 across a wider width of an absorbent
core, a containment layer 30, or other base web. Further, nozzles
76 need not be arranged in a linear array. Thus, nozzles 76 can be
arranged in a virtually unlimited number of nozzle patterns so long
as the nozzles provide sufficient quantity of fibers 40 distributed
on the underlying substrate in a desired weight and a desired
pattern, typically a uniform distribution pattern. Individual
nozzles 76 can be controlled, e.g., intermittent operation, to vary
the width and area covered by the spray patterns. Further, the
amount of resin being deposited by individual nozzles 76 can also
be controlled.
Nozzles 76 can be controlled such that heavier application of
fibers 40 occurs in some areas of absorbent sausage 20, and less
heavy application of fibers 40 occurs in other areas on second
surface 36 of absorbent sausage 20. For example, in the embodiment
of FIG. 3, increased fibers 40 can be applied in the middle of
absorbent sausage 20 and a smaller quantity of fibers 40 can be
applied at the ears of the absorbent sausage. Thus the amount of
fibers 40 can be varied in the cross-direction of absorbent sausage
20. This arrangement conserves the amount of molten fibers 40
applied to form stabilization layer 65 and reduces the overall cost
of products so formed.
In other embodiments, nozzles 76 can be intermittently operated to
vary the amount of fibers 40 applied in the machine direction. For
example, in the embodiment of FIG. 14, fibers 40 can be randomly
applied to absorbent pad 90 at locations where the pad is present
and not applied at locations where the pad is not present during
formation of the absorbent article. This arrangement conserves the
amount of fiber 40 applied to form stabilization layer 65 and thus
reduces the cost of products made by this process.
FIG. 6 shows the output end of a single exemplary nozzle 76 of
spray nozzle assembly 38. Nozzle 76 includes a single resin
aperture 78 for exhausting resin fiber 40. Multiple gas apertures
80 are generally -evenly spaced about resin aperture 78. Resin
aperture 78 preferably is centered on the output end of nozzle 76.
In a preferred nozzle, resin aperture 78 has a diameter of about
0.025 inch and gas apertures 80 have diameters of about 0.030 inch.
In operation, gas apertures 80 continuously exhaust gas which
control the application of resin fiber 40 to absorbent sausage 20.
The design of the nozzle 76, i.e., the diameter of resin aperture
78, and the diameter and angle of gas apertures 80 cause random
movement of fiber 40. The random movement of resin fiber 40 creates
the random weblike pattern exemplified in stabilization layer 65
and shown in FIG. 4. Compressed gas aperture 80 preferably has a
total throughput of between about 0.4 and about 0.8 standard cubic
feet per minute. Resin aperture 78 preferably has a total
throughput of between about 3 pounds per inch per hour and about 5
pounds per inch per hour of resin fiber 40 for the meltspray
embodiment
While the preferred gas is air, other gases and mixtures of gases
can be utilized. The compressed gas attenuates the resin exiting
resin aperture 78, thus to form elongated, and correspondingly
thinned, resin fibers 40. To the extent gas apertures 80 are of a
different diameter than the above recited 0.030 inch, the velocity
and flow of gas exhausted from the respective apertures is changed,
causing the fibers to be drawn more or less severely. Such drawing
changes the diameter of the resultant fibers 40.
Multiple gas apertures 80 and resin aperture 78, in combination,
spray molten resin fibers having a random pattern. Such fibers are
soft when sprayed. In forming stabilization layer 65, illustrated,
multiple nozzles 76 exhaust a corresponding multiple number of
fibers. Gas from multiple gas apertures 80 imparts random patterns
to the multiple fibers which, in combination, form the weblike
pattern of stabilization layer 65 shown in FIG. 4. While six gas
apertures are shown for a given nozzle in FIG. 6, more or fewer gas
apertures can be utilized, so long as the exhaust gas from the gas
apertures of a given nozzle effectively controls resin fiber 40
being exhausted from resin aperture 78. The resin fibers so formed
typically have a diameter from about 8 microns to about 73 microns,
and preferably fiber diameters sized from about 20 microns to about
40 microns. Fibers larger than 80 microns tend to be tactually
noticeable to the user of the absorbent article made therefrom.
Thus, larger fibers tend to impact negatively on the overall
comfort and aesthetics of an absorbent article so constructed. The
resin fibers generally are continuous in length when meltsprayed
onto a substrate, such as second surface 36 of absorbent sausage 20
or containment layer 30.
Meltspray systems can include a separate gear pump stream (not
shown) for each nozzle 76 or module to deliver resin fibers 40
under pressure toward absorbent sausage 20.
Heated resin delivery line 46, heated resin recirculation line 48
and gas heater 50 allow the meltspray system to maintain
temperature of thermoplastic resin, even when meltspray is applied
intermittently or shutdown for an extended period of time. Thus,
upon restart, the meltspray system generates very little waste
material as compared to a corresponding meltblowing system. One
example of intermittent or pulsed operation of meltspray nozzle
assembly 38 can be for providing no resin, or less resin, on an
area of absorbent sausage 20 that is away from the crotch portion
of the final absorbent article, and therefore requires less
integrity.
Other equipment which can be utilized for spray nozzle assembly 38
can be found in columns 14-16 of U.S. Pat. No. 5,227,107. European
Patent Application 0 685 213A2 published Dec. 6, 1995, and hereby
incorporated by reference in its entirety, discloses specific
meltspray equipment and some resin materials useful in the
invention.
Another exemplary adhesive spray assembly and nozzle is set forth
in U.S. Pat. No. 4,785,996 to Ziecker et al, the disclosure of
which is hereby incorporated by reference in its entirety. FIGS. 2
and 3 especially, show details of an exemplary nozzle useful for
applicants'invention.
Meltblowing apparatus, while less preferred, can also be utilized
with the invention. Typical meltblowing devices have orifices on
the order of about 0.0145 inch in diameter, and have 30 or so such
orifices per cross-directional inch of a die tip, and two opposing
air slots configured on each side. Like meltspray, once high
pressure air exits the die tip, it rapidly expands, thus
attenuating the molten resin streams exiting the respective die
tip. For applicants'invention, the melftblowing apparatus must
output fibers having a diameter of at least 8 microns. Smaller
diameter fibers tend to form an impermeable layer on absorbent
sausage 20. Smaller fibers also tend to deform less, and thus,
conform less to the surface of the absorbent sausage.
Meltblowing apparatuses useful in the present invention receive
heated resins from a melt tank and apply the resins to a material,
but have no recirculation means. Therefore, meltspray apparatuses
generally have a quicker start-up time and reach operating pressure
sooner than meltblowing systems.
Melt tank 42, gas heater 50, and spray nozzle assembly 38 generally
are controlled by a conventional central controller (not shown),
such as an ANAPHASE.RTM. controller made by Nordson Corp. of
Duluth, Ga. Such electrical controllers include panel annunciator
alarms, status indicators, control switches, and other control
mechanisms. The central controller can monitor and control all
temperatures including the temperatures in melt tank 42, resin
delivery line 46, resin recirculation line 48 and gas heater
50.
Debulker 60 generally comprises a nip formed by rolls 58A, 58B.
Debulker 60 controls the thickness of absorbent sausage 20 by
compressing the sausage in the nip, between rolls 58A, 58B.
Debulkers are well known conventional devices that can be utilized
for controlling the thickness of absorbent pads.
After containment layer 30 is applied to first surface 34, and
stabilization layer 65 is deposited onto second surface 36,
absorbent sausage 20 passes through debulker 60, and the absorbent
sausage advances along path 64 for further processing.
FIG. 7 shows a second embodiment of the invention wherein the
prefix "1" on the element numbers indicates the second embodiment.
Second and third digits are used in common with the first
embodiment to represent structure corresponding to like structures
in the first embodiment. System 108 includes fiberizer 110 which
breaks up fiber board into absorbent material and ejects it into
forming chamber 112 and deposits it on forming drum 114. Forming
drum 114 generally continuously rotates in the direction of arrow
115. Forming drum 114 has a scarfing roll 116 nearby which shaves
absorbent material to reduce the thickness of absorbent sausage
120. Supply device 122 supplies containment layer 130 to transfer
conveyor 157. In this embodiment, transfer conveyor 157 receives
containment layer 130 and receives absorbent sausage 120 adjacent
the containment layer. First surface 134 of absorbent sausage 120
contacts containment layer 130. Second surface 136 of absorbent
sausage 120 adjacent the spray nozzle assembly 138 receives resin
fiber 140. Heated melt tank 142 receives particulate resin from a
storage hopper 144 and heats it to a molten state. A heated resin
delivery line 146 delivers melted thermoplastic resin to spray
nozzle assembly 138. A heated recirculation line 148 recirculates
unused resin back to melt tank 142 for reuse.
Compressed gas supply 152 supplies compressed gas to gas heater
150. Gas heater 150 heats the compressed gas, such as air, to a
desired gas temperature. Heated gas supply line 154 supplies the
heated compressed gas to spray nozzle assembly 138. Spray nozzle
assembly 138 deposits resin fiber 140 onto second surface 136 of
absorbent sausage 120 to form a stabilization layer. Absorbent
sausage 120 advances on transfer conveyor 157 to first and second
nip rolls 158A, 158B comprising debulker 160. Debulker 160 varies
the thickness of absorbent sausage 120 by controlling the
compression force at the nip. From debulker 160, absorbent sausage
120 advances to transfer conveyor 162. Arrow 164 indicates a path
leading absorbent sausage 120 to further processing stations.
Exemplary such further processing stations are shown in FIG. 12
will be described in detail later.
FIG. 9 shows first and second opposing portions 172, 174 of
containment layer 130 extend outwardly beyond respective edges 166,
168 of absorbent sausage 120. As shown in FIG. 8, for example,
resin fiber 140 does not generally contact or reach containment
layer 130.
In the embodiment of FIG. 9, spray nozzle assembly 138 sprays resin
fiber 140 across substantially the entire width "W" of second
surface 136 of absorbent sausage 120, optionally somewhat beyond
the outer edges of the absorbent sausage, and onto at least part of
first portion 172 and opposing second portion 174 of containment
layer 130. As with the embodiment of FIG. 8, resin fiber 140
quickly cools and hardens, forming stabilization layer 165. Thus,
containment layer 130 and stabilization layer 165 can, in
combination, encompass absorbent sausage 120. Stabilization layer
165, of course, remains porous with respect to liquids.
FIG. 10 discloses another embodiment of the invention. The
embodiment of FIG. 10 is essentially the same as the embodiment in
FIG. 7, except absorbent sausage 120 exits from the opposite side
of forming drum 114 and more importantly, a supply roll 179
containing a second pre-formed containment layer 181 provides the
second containment layer for the absorbent sausage. Further, the
preferred arrangement of applying molten fibers 140 after debulker
160 is shown in FIG. 10. A first containment layer 130 is placed in
surface-surface relationship with first surface 134 of absorbent
sausage 120. Second containment layer 181 advances along a path and
about turning roll 191 toward absorbent sausage 120. Second
containment layer 181 is then applied in surface-to-surface
relationship to second surface 136 of absorbent sausage 120 at nip
rolls 158A, 158B.
Second pre-formed containment layer 181 can comprise a narrow strip
of forming tissue as shown in FIG. 11. Second preformed containment
layer 181 can stabilize and support absorbent fluff of absorbent
sausage 120. As shown in FIG. 11, second containment layer 181
comprises a narrow layer across a central portion of absorbent
sausage 120. First and second edges 183, 185 of second containment
layer 181 extend along the outside length thereof.
Second pre-formed containment layer 181 can have a width from about
2.5 inches to about 9 inches. An exemplary forming tissue has a
porosity of approximately 400 cubic feet per minute per foot
squared, and dry strength of about 730 grams.
Spray nozzle assembly 138 in FIG. 10 deposits resin fibers 140 onto
absorbent sausage 120, second containment layer 181 and first and
second portions 172, 174 of first containment layer 130. As shown
in FIG. 11, nozzles in the middle and outer section of spray nozzle
assembly 138 can be turned off, especially in a meltspray system,
such that a first stabilization layer 165A of resin fibers 140 is
applied to absorbent sausage 120 between outside edge 166 of
absorbent sausage 120 and outside edge 183 of second pre-formed
containment layer 181. Other nozzles of spray nozzle assembly 138
can simultaneous spray resin fiber 140 onto absorbent sausage 120
to form a second stabilization layer 165B between outside edge 168
of absorbent sausage 120 and outside edge 185 of second containment
layer 181. In this manner, portions of absorbent sausage 120 not
covered or supported by second pre-formed containment layer 181 can
be stabilized. As shown in FIG. 11, the central region of absorbent
sausage 120 in surface-to-surface relationship with second
containment layer 181 need not have resin fibers 140 sprayed
thereon. In some embodiments, adhesive can be applied to second
containment layer 181 before placement onto absorbent sausage
120.
In the embodiment of FIG. 11A, individual nozzles of spray nozzle
assembly 138 can be controlled such that resin fibers are deposited
onto first and second portions 172, 174 of first containment layer
130, as well as deposited on absorbent sausage 120. Further,
individual nozzles can also be controlled such that resin fibers
are deposited in contact with second containment layer 181
proximate outside edges 183, 185 thereof. Thus, the entire
absorbent sausage 120 can be surrounded by containment layers 130,
181 and stabilization layers 165A, 165B of resin fiber material.
Such an arrangement stabilizes the fluff material of absorbent
sausage 120 and improves the integrity thereof. Surprisingly, the
arrangement of FIGS. 10, 11 and 11A closely approximates the
functional form of absorbent articles currently being manufactured,
while significantly reducing cost of the absorbent articles by
reducing the amount of containment layer material, such as forming
tissue, needed to manufacture the absorbent article.
FIG. 12 shows exemplary further processing apparatus that forms
absorbent articles which include absorbent sausage 20 as an element
thereof. A combination of absorbent sausage 20, containment layer
30, and stabilization layer 65, is graphically represented by arrow
85 in FIG. 12.
A water trimming device 82, or other conventional trimming device,
trims excess material from first and second portions 172, 174 of
containment layer 130 near outside edges 166, 168 of absorbent
sausage 120 of FIG. 9. Water trimming device 82 follows the shape
of absorbent sausage 120 corresponding to a "T". Preferably about a
1/2 inch width for each respective first and second portion 172,
174 of containment layer 130 is retained, extending outwardly from
each respective outside edge 166, 168 of absorbent sausage 120.
FIG. 13 shows absorbent sausage 120 after parts of first portion
172 and second portion 174 have been trimmed away. For purposes of
illustration only, stabilization layer 165 is not shown in FIG. 13.
In those embodiments where stabilization layer 165 is trimmed along
with containment layer 130, a mechanical knife cutter preferably
can be utilized, rather than water trimming device 182, in order to
effectively cut resinous layer 165.
After trimming of containment layer 130, trimmed absorbent sausage
120 advances as graphically represented by arrow 85A in FIG. 12.
Absorbent sausage severing device 84 then severs absorbent sausage
120, including layers 130 and 165, into individual absorbent pads.
Dashed lines 86 in FIG. 13 show exemplary locations where absorbent
sausage severing device 84 severs absorbent sausage 120 across its
width to form individual absorbent pads 90. Absorbent pads 90 are
graphically represented by arrow 90 in FIG. 14. Such absorbent
sausage severing devices are well known in the art and include, for
example, nip rolls having a cutting element mounted on one of the
rolls thereon, and other conventional devices.
Main tacker 92 mounts and secures discrete absorbent pads 90
between an outer cover and a bodyside liner to create an absorbent
article sausage represented by arrow 94 in FIG. 12. Main tacker 92
is a conventional apparatus for forming absorbent articles on
absorbent article sausage 94. Referring now to FIG. 14, preferably,
hot melt adhesive is sprayed onto bodyside liner 102 and/or outer
cover 104 (both shown in FIG. 15) to provide permanent securement
of outer cover 104, bodyside liner 102, and absorbent pad 90, to
each other at main tacker 92. Main tacker 92 includes a nip
applying pressure to the several elements to ensure securement of
the elements to each other. Absorbent pad 90, fed to main tacker
92, includes containment layer 130 and resinous stabilization layer
165 of fiber 140. While adhesive and pressure at the nip of main
tacker 92 can secure the above elements, ultrasonic bonding and
other methods of securement are contemplated as being
acceptable.
Absorbent article web severing device 96 receives absorbent article
sausage 94 as shown in FIG. 12, and severs the absorbent article
web into individual absorbent articles 100. FIG. 14 shows a
complete absorbent article 100. Absorbent article 100 includes
T-shaped absorbent pad 90 shown in dashed lines therein. Bodyside
liner 102 comprises the surface of the absorbent article closest to
the observer in the view of FIG. 14. A cross-sectional view of
absorbent article 100, shown in FIG. 15, and taken across the width
of the article of FIG. 14, shows the relationship between the
various elements. A chassis formed by bodyside liner 102 and outer
cover 104 encases, and thus encompasses, absorbent pad 90.
Containment layer 130, comprising a barrier tissue, is located
between bodyside liner 102 and absorbent pad 90. Containment layer
130 resists the return of liquid toward bodyside liner 102 after
liquid passes therethrough into absorbent pad 90 and migration of
superabsorbent material towards the user of the absorbent article.
Stabilization layer 165 is located between absorbent pad 90 and
outer cover 104 and is adjacent the outer cover. Stabilization
layer 165 provides enhanced integrity to absorbent pad 90 and
reduces the likelihood of exudates discoloring outer cover 104 of
absorbent article 100. Stabilization layer 165 also assists in
protecting outer cover 104 from being damaged or penetrated by
material, especially particles of superabsorbent material migrating
from absorbent pad 20C.
Other steps and apparatus for applying leg cuffs, waist bands,
containment flaps, attachment ears, or the like are considered
conventional and are within the scope of this disclosure. For
example, a surge layer (not shown) can be located between bodyside
liner 102 and containment layer 130. The surge layer allows
exudates to spread over substantially the entire absorbent pad 90.
Thus the surge layer assists absorbent pad 90 in absorbing a sudden
large amount of urine.
Those skilled in the art will now see that certain modifications
can be made to the invention herein disclosed with respect to the
illustrated embodiments, without departing from the spirit of the
instant invention. And while the invention has been described above
with respect to the preferred embodiments, it will be understood
that the invention is adapted to numerous rearrangements,
modifications, and alterations, all such arrangements,
modifications, and alterations are intended to be within the scope
of the appended claims.
To the extent the following claims use means plus function
language, it is not meant to include there, or in the instant
specification, anything not structurally equivalent to what is
shown in the embodiments disclosed in the specification.
* * * * *